GlaxoSmithKline's chief executive, Sir Andrew Witty, doubled his bonus last year, collecting £1.9m even after the massive corruption scandal the company still faces in China cut his payout by £245,000.

Witty received a pay and shares package of £6.5m after GSK had the best year ever in its labs, but in light of the China scandal the company's remuneration committee decided not to award his maximum possible bonus of £2.12m.

Tom de Swaan, who chairs the committee, wrote in a letter to shareholders: "Both Sir Andrew and the board are mindful of the impact this issue has had on the reputation of the company. As a result, the bonuses awarded for 2013 were lower than they otherwise might have been."

Witty's salary rose to £1.06m from £1.03m in 2012. In addition, he received benefits of £67,000, as well as share awards worth £3.5m based on the company's performance. This took his annual pay and shares package to £6.5m from £3.9m in 2012. Including his pension, Witty's total package was £7.2m last year, up from £4.4m in 2012.

The Chinese authorities last year branded the company a "criminal godfather", accusing it of running a £320m slush fund to bribe doctors and hospital officials with cash payments and visits to prostitutes. GSK said on Thursday that the investigation in China was continuing and that it was co-operating with the Chinese authorities.

A GSK spokesman said: "Andrew Witty's bonus reflects GSK's very strong performance in 2013 which included receiving the highest number of product approvals of any company, meeting the top end of our financial guidance and delivering the best total shareholder return since the formation of the company, with more than £5bn returned to shareholders.

"His bonus has been reduced from the maximum possible as both Andrew and the board are mindful of the impact the investigation in China has had on the reputation of the company."

In 2012, GSK paid a $3bn (£1.8bn) fine for misselling drugs in the US, the biggest healthcare fraud settlement in American history. At the time, Witty was apologetic and announced his determination to stamp out such sales practices, only to see the company embroiled in another scandal within a year.

The pharmaceutical giant's head of global research & development and vaccines, Moncef Slaoui, received a total remuneration package of $8.4m last year, up from $6.6m in 2012.

GSK hailed an exceptional year for research and development in 2013, with six major products being approved by in the US, nearly a fifth of all regulatory approvals in the country. Return on R&D, an internal target, improved to 13% from 12%. Turnover rose 1% to £26.5bn last year, lifting pre-tax profits by 0.7% to £6.6bn.